Doug's A/C System, R&D/Build Thread Options

[dlee6204]

I thought I would document my A/C adventure in the hopes that it would be a good reference for anyone else considering A/C. I’ll first touch base on the stock system and on custom options and then start building my own system to start testing on. I’ve working on a few systems before but I'm sure there is someone that knows more than me so don't be shy sharing or adding anything. (IMG:style_emoticons/default/smile.gif)


To begin things off here is one of the better overviews of an A/C system. Follow the link and you can see a breakdown of the whole system.


http://www.movacs.com/How%20it%20works/index.html





Anytime I refer to the stock system I will be referring to the dealer installed VPC system mostly because the only A/C cars I had came with this system and I have plenty of parts around.

I also borrowed some photos off this site so if I used any of yours... Thanks. (IMG:style_emoticons/default/smile.gif)


Compressor:

The compressor that came on dealer installed A/C systems was a York Piston style compressor that had a capacity of 6 cubic inches/Rev. From what I could find it used about 7-10 horsepower from the engine. You can still use this compressor however there are better, more efficient options out there. When choosing a new compressor it is a good idea to find one with a similar capacity. In this case going bigger does not mean better. An A/C system works as a whole unit and if you dramatically change one aspect of it, you will likely see negatives effects elsewhere. Choosing a compressor that’s too big will overwork the system, yielding no little to no benefit, and create a not-as-efficient system. During my search I looked mostly at Sanden style compressors so that's what I'll be referring to in my build. Using a modern compressor like the Sanden will only use about 3-4 hp from the engine. I have heard quite a few people use the Sanden 508 compressor with good results. It has an approximate displacement of 8 cubic inches/rev, which IMO is slightly more than I'd like to make a jump to. I'm not saying it wouldn't work, it obviously works, however I think I will get slightly better results and pressures using the Sanden 507 (approx. 7 cubic inches/rev). The SD507 is also slightly smaller in size than the 508.

Here is a picture of the York Compressor


A side by side with the SD507





And here is a SD508

[andys]

I know I'm delinquent with posting photos of my AC install, so meanwhile I'll describe how I routed my hoses as it differs from most. I ran my #6 and #8 hose from the front trunk low on the passenger side through the bulkhead, under the fuel tasnk, then into the foot well which give me a direct shot with the #6 hose to the expansion valve on the evaporator. The #8 and the #10 (suction side from the evap) travel along passenger side floor Adel clamped to the corner at the floor/long intersection. The hoses are hidden by the carpet, and are un-noticeable (I know, I need to post some photos). The #8 and #10 continue to the firewall where I have 90 degree hose ends with charge ports coupled to two bulkhead fittings. These are positioned such that they enter the engine bay below the tin just under the hell hole area. The one photo I do have is durring the mock-up stage.....the charge ports are no longer where you see them in the pic.....This gives you an idea of the routing to the LS1 compressor.

The reason I did it as described above, is I wanted to avoid running the AC hoses in the wheelwell (wide front tires there), as well as minimize the number of holes punched through the various panels, etc.

Andys